The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent the work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
A Brush-Less Direct Current (BLDC) motor, also known as an electronically commutated synchronous motor, uses driver circuits to electronically commute one or more windings of the motor. The driver circuits periodically connect and disconnect the one or more windings of the motor to a supply voltage and a ground, and a current then flows through the one or more windings, generating one or more magnetic fields within the motor.
When the driver circuits disconnect the one or more windings from the supply voltage and the ground, the magnetic fields within the motor cause the current to continue flowing through the one or more windings. The continued flow of the current generates a voltage across the one or more windings. The voltage generated by the continued flow of the current rises until a path is found for the current to flow through.
In some driver circuits, the path includes one or more of protection diodes connected across conduction terminals of transistors of the driver circuits, body diodes intrinsic to the transistors of the driver circuit, and reactive components, such as capacitors, associated with a circuit that supplies power to the driver circuit.
The flow of the current dissipates energy stored in the magnetic fields in the motor. When the energy in the magnetic fields is completely dissipated, the current flow ceases.